Living in a tiny house has caught on trend for all the right reasons.
They are cheaper, cozy, portable (in the case of trailer homes), and more efficient than standard housing.
When you are looking to have a home but cannot afford a bigger unit, a tiny house will make your dream come true.
Some people also choose this path for environmental reasons. For one, tiny homes require a small piece of land hence a smaller carbon footprint.
You can find renewable energy sources or go completely off-grid – both of which are good for the environment.
Ever thought about waste disposal with regard to a tiny house?
Most specifically, how human waste is taken care of in this way of living.
Well, one of the eco-friendly methods of processing waste is using a septic system.
In this guide, I will delve deep into tiny house septic systems.
What Kind Of Septic System Is Best For A Tiny House?
Here are a few options to consider:
1. A Typical Septic System
A typical septic system used in standard housing is a good option for a tiny house.
As long as you have the space for the tank and the leach field, you can have one installed on your property.
2. An Anaerobic Septic System
An anaerobic septic system adds oxygen to a septic tank to boost the effectiveness of the bacteria in the tank.
Since waste is processed extensively in the tank, this system requires a small leach field compared to conventional systems. As such, it is great for a tiny house.
The only downside is that it is three times more expensive than your traditional system.
Related: How Much Does A Concrete Septic Tank Cost To Install?
3. Above-Ground Septic Tank
For people looking for a temporary waste management problem or those that travel a lot with their tiny houses, having an above-ground septic tank is a lifesaver.
This system consists of a holding tank meant to carry wastewater until it can be safely disposed of.
But given that septic tanks aren’t FDA approved to hold or transport potable water, are above-ground tanks legal? Well, check out our post on that here: Are Above-Ground Septic Tanks Legal?
4. Low-Pressure Dosing System
If your tiny house is located in areas with clay soil or without enough soil to hold standard septic systems, then you can opt for a low-pressure dosing system (LPD).
In an LPD, wastewater is treated and then pumped into the soil several times a day.
LPD systems are efficient and can handle small volumes of wastewater, making them suitable for tiny houses.
The only downside is that they require more maintenance than traditional septic systems though not as much as aerobic systems.
5. Mound systems
Another septic system option that you can consider if your site is located in areas with poor soil conditions (like high groundwater table, shallow soil depths, and shallow bedrocks) is the mound system.
A mound system comprises of elevated mound of sand or gravel that provides suitable environment for wastewater treatment.
While it is easy to install and doesn’t have costly repairs compared to other septic systems, it requires more space for the trench and you may have to deal with odor issues if waste water doesn’t leach fast enough into the ground.
6. DIY septic tank
Last but not least, you can also install your own DIY septic tank for your tiny house.
You just have to learn how to dig a hole for the tank, install it, connect the necessary pipes, cover the pit, and direct the wastewater to the soil.
It is a tricky undertaking but one that will save you a lot of money in the process.
Tiny House Septic System Size
Tiny houses don’t come in one size. Some are much larger, others smaller, and some in between.
Consequently, the septic tank sizes for such houses differ as well.
The size of the tank depends on its usage. If you live in a tiny house that accommodates two people for the most part, a 750 or 900-gallon tank should be sufficient.
However, if you are more than two, it is safe to install a 1200-1500 gallon septic tank. This also applies to a tiny house that get visitors a lot.
The general zonal regulations for building septic systems for tiny houses in your area also matter.
In most cases, you’d be required to put up a tank of not less than 1000 gallons.
Cost Of A Septic System For A Tiny House
Now that you have an idea of the type of septic system to invest in, the next question to ponder is the money.
The cost of a tiny house septic system is pretty much the same as that of a typical system.
Here’s a breakdown of the costs anticipated.
- Soil Test And Land Survey: First things first, you need to hire an expert to carry out percolation tests and land survey of your land before installing a septic system. This costs $500 to $1,000.
- Tank: The biggest purchase you’ll make on your septic system is the septic tank. The material of construction and size affect the cost. Here, you will spend anything from $500 to 1,600.
- Labor: This depends on the work done on the septic system. A big heavy tank obviously needs a lot of work and will consequently cost more than a smaller and lighter one. Additionally, if the location of the tank and drain field needs to be cleared, the cost of labor will go up as well. To build a tiny house septic tank, expect to part with $1500 and $3,000.
- Permits: Irrespective of the type of septic system you decide to install for your tiny house, you need to get proper permits. The type of permits you need and their respective costs depend on your local government’s laws and regulations. On average, be ready to part with between $300 and $1800 for permits.
Related: Do You Need A Permit To Repair A Septic System?
Summary of the Cost of installing a tiny house septic system
| Lower cost | $3,000 |
| Higher cost | $6,000 |
| Average cost | $4,500 |
Factors That Affect Septic System For A Tiny House Cost
Why does the cost of building a septic on one tiny house differ from the next house?
Well, there are certain factors that come into play when installing one. Check them out below.
I. Material of the tank
Septic tanks come in different materials. The common ones include plastic and steel but you can also get one in plastic and fiberglass.
Prices differ based on the strength and durability of the material of construction.
Plastic is the cheapest but it doesn’t have longevity.
Fiberglass is the most expensive as it can stay up to 40 years.
Steel and concrete are somewhere in between.
Take a look at the table below to know the difference in cost among the different septic tank materials in the market.
| Material | Lower cost | Higher cost |
| Plastic | $500 | $1,000 |
| Steel | $800 | $1,000 |
| Concrete | $750 | $1,700 |
| Fiberglass | $1,200 | $1,600 |
II. Size Of The Tank
A big tank needs more space and more work to install. This not only pushes the labor cost up but the materials as well.
III. Location Of The Septic System
Assuming you own a large piece of land, you can opt to place your septic tank a distance away from your tiny house.
That means more piping, added pumps, and other materials.
Ultimately, this translates to a higher cost.
IV. Maintenance
When calculating the cost of installing a septic system for your tiny house, you should also factor in ongoing maintenance costs.
Maintaining a tiny house septic system follows the same protocol as a typical septic system.
You’ll need to have the tank pumped every 3 – 5 years as per EPA’s regulations.
If you have more people living in your tiny house, the tank will need to be pumped strictly after every three years.
Else, if it is only you or an extra person at home, it can go for five years without a problem.
Also, use only septic-safe products in your bathroom to avoid clogging and backups.
Lastly, you may want to inspect your tank often and carry out the necessary repairs before they graduate into huge projects.
V. Local Regulations
Some jurisdictions may require different types of permits and/or specific types of systems or technologies (like advanced treatment systems), which can drive your costs further.
Even worse, failure to comply with some of these regulations often attracts penalties and fines and even removal of the whole system, which can be costly and frustrating.
How To Save On Installation And Maintenance Of Tiny House Septic System
Installing a tiny house septic tank is not cheap. So, is there any strategy you can use to save money? Here are a few suggestions:
- Wait for low seasons: Some septic tank companies offer reduced prices on their services during specific times of the year. Ask yours if they have such plans. If they do, take advantage of them (if you are not in a hurry).
- Apply for septic system grants: Some states and towns offer grants for the replacement and installation of septic systems. If you are lucky to have access to one, don’t waste the opportunity.
Related: How to Apply For Septic Tank Grant
- Get Multiple Estimates: Before making any contract, receive as many estimates from as many licensed septic tank companies as you can. Read reviews of each one and select the most affordable option for the project.
- Opt For A Smaller Septic System: Installing a smaller septic system that is appropriate for the size of your tiny house can help you save money on installation and maintenance costs.
- Maintain It Regularly: Regular pumping and inspection of your system can prevent clogs, backups, and other problems that can be expensive to fix.
- Keep the tank closer to your tiny house to cut on material costs
- Use cheaper but quality materials.
- Make it a DIY project if you are capable—i.e you have the necessary skills and tools.
FAQs
A. Can a composting toilet be used instead of a traditional septic system in a tiny house?
Yes. In fact, most tiny houses use composting toilets. However, these are smelly, need lots of maintenance, and aren’t permitted in some states.
B. How do I choose the right septic system for my tiny house?
It depends on your needs. If you transport your home a lot, go for a temporary option. Otherwise, a conventional system will do. If money isn’t a problem, choose an anaerobic system.
C. Can a septic system for a tiny house be installed off-grid?
Yes. Provided you have enough power from renewable sources to run your pumps.
D. Can a septic system for a tiny house be installed in any soil type?
The best type of soil is loamy soil. However, if you have sandy or clay soil, you can get a special kind of septic system such as a mound or anaerobic septic system.
Speak to your local septic system installers about this.
You may also want to check: What Is The Best Septic System For Clay Soil?
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